package cn.wonderland.filter;

import com.alibaba.fastjson.JSON;
import lombok.extern.slf4j.Slf4j;
import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.GlobalFilter;
import org.springframework.core.Ordered;
import org.springframework.core.io.buffer.DataBuffer;
import org.springframework.http.HttpStatus;
import org.springframework.http.server.reactive.ServerHttpResponse;
import org.springframework.stereotype.Component;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;

import java.nio.charset.StandardCharsets;
import java.util.HashMap;
import java.util.List;

@Slf4j
@Component
public class LoginCheckFilter implements GlobalFilter, Ordered {

    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {

        // 1.获取请求头，拿到token
        List<String> token = exchange.getRequest().getHeaders().get("token");
        log.info("全局---token为：{}", token);

        // 2.判断token请求头是否为空，如果为空抛出异常，说明未登录
        if (token == null || token.isEmpty()) {
            // 1.响应对象
            ServerHttpResponse response = exchange.getResponse();
            // 2.构建错误结果
            HashMap<String, Object> data = new HashMap<>();
            // 3.设置响应信息
            data.put("code", 401);
            data.put("success", false);
            data.put("message", "登录校验失败，请重新登录！");

            DataBuffer buffer = null;
            //  4.转换参数，包装buffer对象
            // 4.1.将数据转换为JSON，再转换为byte数组
            byte[] bytes = JSON.toJSONString(data).getBytes(StandardCharsets.UTF_8);
            // 4.2.将byte数组包装到DataBuffer对象中，用于响应给浏览器，构建响应内容
            buffer = response.bufferFactory().wrap(bytes);

            // 5.设置完成响应，不会继续执行后面的filter
            // 5.1.设置响应状态为401
            response.setStatusCode(HttpStatus.UNAUTHORIZED);
            // 5.2.设置响应格式
            response.getHeaders().add("Content-Type", "application/json;charset=UTF-8");
            // 6.把结果写给客户端
            return response.writeWith(Mono.just(buffer));

        }
        log.info("Token不为空 ，放行");
        // 7.token不为空，继续执行后续filter
        return chain.filter(exchange);
    }
    @Override
    public int getOrder() {
        return 0;
    }
}